Cleanup /home/chronos before every pyauto tests on chromeos
Cleanup /home/chronos before every pyauto tests on chromeos

Cleanup files in /home/chronos not just /home/chronos/user

BUG=
TEST=

Review URL: http://codereview.chromium.org/6625073

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@77231 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser